There’s something organic about the way it all happened. A 60-year-old Buffalo man drove around 90 minutes to just outside of Rochester to buy a Body Opponent Bag — now called “Bob the dummy” — on Facebook Marketplace two days before the city’s first playoff game in 15 years. A group of younger Sabres fans known as the Blade Gang veered around KeyBank Center before that same April afternoon. And when Nick Mastrocovo moved his dummy — donning a Bruins jersey for the Sabres’ first-round opponent — closer to the Blade Gang during the pregame festivities April 19, one member landed a punch. Everyone erupted. Another member tackled the dummy from behind. A viral moment was born. Mastrocovo and his cousin returned for Game 2 in referee jerseys, just in case something got out of control after the added attention. The Blade Gang traveled to Boston for road games. Playoff hockey in Buffalo suddenly had more than a pulse. It rapidly became the epicenter of the tournament.…